Rotating electric liquid switch



Oct. 7, 1947! c. J. AANDEWIEL ROTATING ELECTRIC LIQUID SWITCH Filed June 22, 1937 Patented Oct. 7, 1947 ROTATING ELECTRIC LIIIQUID SWITCH .'Cornelis Johan Aandewlel, Wassenaar, Netherlands, assignor toFirma Eerhard-Aandewiel,

Wassenaar, N ether-land lands 5, a firm of the Nether- "Application June 22, 1937, Serial No. 149,767 In the Netherlands October 17, i936 Section 3, Public Law 690, August 8, 1946. Patent expires October 17, 195.6

Claims.

The invention relates to a rotating electric liquid switch, more particularly to a switch which is adapted to interrupt or to close a pair of contacts by means of the inertia of the liquid present.

The switch according to theinvention may be used for numerous purposes and is particularly suitable for controlling the action of some rotating machine part. If, for example, the switch according to the invention is to serve in a warning device for signalling the rotation or the stopping of a rotatory machine part, e. g., a wheel or a shaft, the said switch is placed in a circuit comprising a power unit and a sound or a light signalling device. The switch may then be constructed so as to close a pair of contacts in such a signalling circuit, either when the shaft or the wheel stops its rotation, or when it starts to rotate. The switch according to the invention is particularly suitable for use as an automatic switching device for a parking or a stop signal apparatus for mechanically propelled vehicles \such as, e. g., motor cars. I

In the accompanying drawing some embodiments of the switch according to the invention are illustrated.

Fig. 1 is an axial section of the switching device through the line 1-1 in Fig. 2.

Fig. 2 is a section at right angles'to the one according to Fig. 1.

Fig. 3 is a section corresponding to Fig. 2 of a second embodiment according to the invention.

Fig. 4 is an embodiment of the invention ap plied to a motor car.

The switch according to the invention comprises a, drum or jacket I made of electrically conducting material, which drum is sealed airtight and liquid-tight by two covers I5, I6 of an insulating material mounted on a rotative spindle 2'. The interior of the jacket or drum I is filled with a suitable insulating liquid, preferably oil, while in the drum there is also provided a blade shaped member 3 having a width that is entirely or partially equal to the axial length of the interior wall of the drum I. This blade 3 at one end is provided with a contact 4, while its other end is pivotally mounted at 5 in a holder 6, held fast to the spindle 2 by means of a bolt I and cooperating nut. A sickle-shaped member 8 is connected to the blade 3 and subjected to the action of a draw-spring 9. The tension of the spring 9 may be controlled by means of a set screw Ill. The other end of the draw-spring 9 is connected to a member 25 fixed to the shaft 2. The spindle 2 is constructed loosely rotatable in the drum I and for this reason the supports II are provided with gaskets I2 which are held in place by nuts I3.

The switching device functions as follows:

The spindle 2 of the switch is coupled with the machine part to be controlled, e. g., with a rotating shaft, in such a way that the said spindle 2 will rotate in the direction of the arrow I4 in Fig. 2. Because of the fact that the drum I is stationary and is filled with oil, the blade 3 with the contact twill be urged away from the interior wall of the drum I by the said oil, against the action of the spring 9, as long as the spindle 2 is rotating. If the wall of the drum I and the contact 4 form two contacts in a signalling circuit, said circuit will remain interrupted, as long as the spindle 2, that is to say the machine part to be controlled continues rotating. As soon, however, as this is the case no longer, the blade 3 will be urged against the wall of the drum I by the spring 9,so that a contact is made, whereby the'signalling circuit is closed.

It has been found that even at a very slow rate of rotation of the spindle 2 the blade 3 will be urged away from the wall of the drum I, if a resilient material is used for the blade 3 or if a suitable tension is selected for the spring 9. The switch according to the invention has the advantage that there will-not be any wearing of the parts, since the mechanism is functioning in oil and in an airtight space, so that there is no burning out of the contacts and also since the contact is only urged against the drum I when the mechanism is at a stand still, so that the contact does not drag against the drum.

It is self-evident that the switch may also be constructed in such a Way that the contact is closed if the spindle 2 starts to rotate and inter rupted when the spindle 2 is stopped. An embodiment of this nature is illustrated in Fig. 3. In this figure the parts likewise illustrated in Fig. 2 are provided with like reference numerals. In this embodiment the contact 4 is replaced by a plate I3 of some insulating material, e. g., fibre, while the member 8 is provided with a small metal roller II which when the spindle 2 is rotating, is urged against the wall of the drum I, so that the contact is closed, since the oil urges the plate I8 away from the said wall.

Fig. 4 represents a motor car in which the switch I 9 is arranged on the driving shaft 20. The drum I is connected by means of a wire 2I with the I battery 22, which battery at the same time is conto a stop and it is extinguished as soon as the shaft 20 starts to rotate.

' It is also possible, of course, to arrange more than one blade 3 side by side on the spindle, which blades, contingently, may co-operate with outer rings which are insulated with regard to each said blade-shaped member, which blade-shaped member during rotation due to the inertia operation of said liquid controls the operation of the switch.

2. Switch according to claim 1 in which the second switch contact is spring-loaded in such a way that when the spindle stops rotating the said contact will rest against the interior wall of the electricity conducting drum which forms the first contact of the switch, whereas when the spindle is rotating the said second contact is urged away from the said wall against the action of the spring, by the liquid.

3. Rotating electric liquid switch comprising a drum filled with an insulating liquid and having a wall made of an electricity conducting material which forms one contact of the switch, and a spindle rotatably and centrally located in the said drum on which is mounted a blade-shaped member provided with the second switch consecond switch contact being spring-loaded in such a. way that when the spindle stops rotating the said contact will rest against the interior wall of the electricity conducting drum which forms the first contact of the switch, whereas when the spindle is rotating the said second contact is urged away from the said wall against the action of the spring, by the 1iquid, the action of said spring being such that the contacts are closed when the spindle is at a standstill and are interrupted when the spindle is rotating.

4. A rotating electric liquid switch comprising a drum filled with an insulating liquid and having a wall made of electrical conductive material which forms one contact of the switch, a spindle rotatably and centrally located in said drum. 9. blade-shaped member in said drum provided with an insulating plate resting against said wall and a rotatable contact roller controlled by said bladeshaped member designed to contact said wall upon rotation of said spindle.

5. .A' switch as set forth in claim 1 in which the rotatable spindle carries a plurality of bladeshaped members insulated from each other, which blade-shaped members are co-acting with a corresponding number of electricity conducting rings insulated from each other and together forming the drum wall.

CORNELIS J OHAN AANDEWIEL.

REFERENCES CITED The following references are of record in the ,file of this patent:

UNITED STATES PATENTS Number Name Date 997,465 Mies July 11, 1911 1,177,548 Southwick Mar. 29, 1916 1,201,564 Daniel Oct. 17, 1916 1,574,370 Curtiss Feb. 23, 1926 1,994,626 Townsend Mar. 19, 1935 

